显微组织观察及EDS在火灾原因判定中的应用

Application of Microstructural Observation and EDS Analysis on Deciding the Fire Hazard Causation

通过对火灾现场的熔珠进行显微组织观察,初步得出由火场高温作用形成的熔珠其显微组织均为等轴晶,没有气孔;而由一次短路形成的熔珠其显微组织则为细小的树枝晶,且有几个不大的气孔。进一步用EDS分析手段判断出,该一次短路熔珠的成分与该车上提取的铜接插件的化学成分基本一致,因此,可以确定导致此次汽车火灾的原因是由于该车上的铜接插件发生短路。

By observing the microstructure of melted bead on the fire scene, the microstructure of melted bead caused by high temperature of the fire was equiaxed grain and no pores. However, the microstructure of melted bead contained fine dendrites and several small pores. Furthermore, EDS analysis was used to detect the composition of melted bead caused by short circuit, which showed that it was the same to that of the copper card. Therefore the fire hazard was caused by short circuit of the copper card.